An eccentric screw pump essentially comprises a screw-shaped rotor mounted rotatably in a stator, which rotor rotates with its longitudinal axis eccentrically around the stator axis. The side of the stator facing the rotor comprises a double-lead helix having a double pitch and corresponding to the rotor shape. The clear space of the stator forms in cross-section a rectangular area with two semicircular areas adjoining the sides lying opposite one another, the diameter of said semicircular areas corresponding to the diameter of the rotor shape. A plurality of chambers of equal size thus arises between the rotor and the stator, in which chambers the delivered material, on account of the different pitches of the rotor and the stator, is moved in its axial direction through the stator. The rotor is usually made from a low-abrasion material such as steel for example and the stator is made, amongst others things, from an elastic material, such as rubber for example.
The elastomer stator inner part is often provided in practice with a steel casing, rubber-like material being vulcanised for example into the casing. On account of its material, the stator is subject to a comparatively high degree of wear, for which reason a replacement of the stator or the stator casing is required at regular intervals. Solutions have repeatedly been sought in the past to keep the maintenance work required for a replacement to a minimum.
An eccentric screw pump with at least one stator made of an elastic material and a rotor mounted in the stator is proposed for example in DE 10 2008 021 920 A1, wherein the stator is provided with segment strips overlapping one another which completely surround the stator.
An eccentric screw pump with a stator casing comprising segments connected to one another in a form-fit manner is disclosed in DE 33 12 197 A1. The form-fit connection is produced by means of a kind of tongue-and-groove joint.
It would however be desirable for a stator with a stator casing comprising segments to be made available, with which the segments could be fitted and removed particularly easily and with little time consumption. The segments themselves, in particular without the use at further auxiliary stabilising elements, should endow the stator with the required rigidity. The known solutions of the aforementioned kind, however, have only a limited suitability.